Editing Understanding the Function Hierarchy (section)

===Events===

An event is a subunit of a run, and is comprised of steps. Just like with a run, users define what actions should take place at the beginning and end of each event in the event action file. These actions are highly variable between applications, but common event level actions are saving initial conditions of the event and saving some final result.

As a rule of thumb, the event should be one instance of whatever the simulation is meant to study. For example, if you wanted to simulate what happens to skin when exposed to sunlight, the event might be shooting an equivalent number of particles from one hour of sunlight at simulated skin. The idea would be to repeat this to come to a conclusion, so it would be a good step.